About 30-80% of chronic substance abusers are estimated to have measurable cognitive deficits of mild to moderate severity. Cognitive impairment is known to have a negative impact on substance abuse treatment outcomes and processes. Specialized treatments and enhancements aimed at improving outcomes for patients with substance use disorders (SUD) have shown some success; but this is still an area in its infancy, and further research is needed. Treatment research in this area cannot advance without the means to identify cognitively impaired persons, but there is currently no time-efficient or resource-conscious way to do so. Neuropsychological assessment is generally prohibitive in drug treatment settings due to constraints on time and resources. Research data also show that cognitive impairment cannot be adequately identified via clinical impression of drug counselors or through self-report. To date, the search for a brief (10-15 minute) cognitive screening instrument sensitive to the mild to moderate impairment observed in SUD patients has been unsuccessful. However, a new cognitive screener (the Montreal Cognitive Assessment Tool: MoCA), which was developed specifically to identify mild cognitive impairment, shows promise as a means to identify these patients. Although brief, the MoCA assesses a range of cognitive domains that are similar to a lengthier test with known sensitivity to the mild to moderate deficits observed in SUD patients. The aims of this study are to assess the validity, accuracy, and clinical utility of the MoCA in identifying cognitive impairment among SUD patients. The Neuropsychological Assessment Battery-Screening Module (NAB-SM) will be used as the reference criterion for determining agreement and rates of correct and incorrect decision classifications. Subjects will be sixty, consecutively admitted adult patients who are recent admissions to either the Partial Hospital or Residential Program at the McLean Hospital Addiction Treatment Program, and who have been abstinent from all drugs of abuse for at least 7 days. Subjects will be individually administered study measures at a single time point. Criterion-related validity of the MoCA will be evaluated through its agreement with the NAB-SM. The kappa statistic (k) for dichotomous data will be used to measure agreement between the MoCA and the reference criterion. Classification accuracy will be assessed by generating a confusion matrix and deriving measures of sensitivity, specificity, positive predictive power, and negative predictive power. Clinical utility will be assessed via a combination of qualitative assessment of patient acceptability and practical considerations. It is hoped that through the proposed research, a means of classifying SUD patients as cognitively impaired or unimpaired will be identified, which will enable treatment research in this area to move forward. Specialized substance abuse treatments and enhancements aimed at improving treatment outcomes for patients with substance use disorders (SUD) have shown some success; but this is still an area in its infancy, and further research is needed. Treatment research in this area cannot advance without the means to identify cognitively impaired persons, but there is currently no time-efficient or resource-conscious way to do so. The specific aims of this project are to assess the validity, accuracy, and clinical utility of a brief cognitive screening instrument in identifying cognitive impairment among SUD patients in a clinical research setting. [unreadable] [unreadable] [unreadable]